This is just a cover while stored, not a towing cover, right? If so, is it stored outside in the sun?
Have you tried Overtons or West Marine? They have a lot of different covers, but I’m not sure how different the cheaper ones are from the eBay ones you’ve dealt with. A decent canvas cover will last a lot longer, but they are quite a bit more $$.
Sent from my iPhone using SoCal Jet Boats